Metal cleaner



Patentedl n s; 1937 {PATENT OFFICE 2,os3,o13 v METAL CLEANER Michael WoFreeman, Detroit, Mich.

No Drawing. Application February 15, 1932, Se-

rial N0. 593,208. Renewed February 11, 1934 5 Claims. 401. 148-8) The present invention relates to the cleaning of metals and more particularly to the preparation of iron and steel surfaces to be subsequently coated with a protective film. The invention 5 be described in connection with steel, but it is in noway limited to that particular metal.

Metal cleaners are used in many arts, and such cleaners are widely used in the manufacture of automobile bodies and metal furniture- In the 10 making of such articles, the metals are usually pickled, shaped, and joined together to give the l desired structure. During the' formirig and join ing of the metal pieces, the metal surfaces become soiled with handling marks. greases of various l5 natures, and the like, and also become corroded so that it is essential that such foreign matter contained on the surface of the metal be removed before coatingthereof with protective films such as by painting, lacquering, metallic 20 plating, and the like.

In the past, it is my understanding that clean ers, including a mineral acid or mixture of mineral acidsphave been used for removing the foreign material from such metal surfaces. The 25 most customary mineral acid employed has been phosphoric acid and/or various'salts thereof.

In the use of these prior art cleaning mixtures,

including the mineral acid, the metal surfaces have first been washed to remove excess of oil 3 and grease, such solvents as commercial gasoline being employed for this purpqsef Subsequent to the washing in this manner. the cleaner has been applied to the metal and, be-

' cause of the ingredients used in the prior art:

' accomplished by the use of hot water to get rid of the free acid or, in lieu of water, a weak base such as ammonium hydroxide-can be used as a neutralizing agent.

50 After washing, the metal surfaces are dried and then painted or otherwise 'provided with the protective coating.

Because of the use of, the mineral acid cleaner, in most cases the metal surface has an undesir- 55 able dark film left thereon. The thorough dryacid. and others.

ing of the cleaned metal prior to painting is of prime importance to the prior art processes.

It is an important object of the present invention to provide a cleaning compound for metallic surfaces including an organic sulphonic acid, 5 mixtures or derivatives thereof, dissolved in a suitable solvent. or mixture of solvents.

Another important object of the invention is to provide such a cleaner which is substantially, if not entirely, devoid ofmineral acids so that after application of the cleaning material, it is not essential to the successful operation to remove said cleaning material from the metal surface.

Thereare numerous other objects of the'invention that will become apparent hereinafter.

Broadly speaking, I produce my improved metal cleaner bymaking a mixture of an organic sulphonic acid, a solvent therefor, and a solvent for these sulphonic acids are: Phenol sulphonic acid;

benzene. sulphonic acid; naphthalene sulphonic acid; toluene sulphonic acid; naphthol sulphonic Obviously, the exact proportions of any mixture will depend upon' the particular organic sulphonic acid used as wellas the solvents included.

In addition, the particular character of metallic I surface to be-cleaned must be taken, into consideration. However, byway of example, I will point r out that the following mixture has been commercially used 'in' the cleaning of automobile bodies in a very satisfactory manner:

. I Percent Crude naphthalene sulphonic acld 6. Denatured alcohoL Water 34 Benze 10 Inthisparticularmixture,thewaterservesas a solvent for the crude naphthalene sulphonic acid, while the alcohol and benzene are primarilyl included for dissolving the grease on the metal so that the sulphonic acid solution will penetrate readily to the surface of the'metal being treated. The alcohol and benzene also, in the example given, happen to be solvents for the sulphonic acid, but it is not essential that all of the solvents used be solvents for the sulphonic acid. Crude naphthalene sulphonic acid is desirable because it not only works very satisfactorily, but is available at reasonable cost on the open margrease. The invention contemplates the use of -ket. In some instances. it may be preferred to include a certain percentage of some such substance as carbon tetra-chloride to decrease the fire hazard of the mixture. .In fact, five to fifteen per cent carbon tetra-chloride can be satlsfac 5 torily added to the above mixture.

In some cases, it may be exceptionally desirable to utilize a cleaning compound that is substantially non-inflammable. Such a mixture can be made by using- Per cent Crude naphthalene sulphonic acid 6 Carbon tetra-chloride 12 Water 29 Alcohol 53 of cleaning solutions containing mineral acids.

Another very important feature of the present invention resides in the fact that while with the prior art cleaners, it is essential that the cleaner be removed before painting, with the present 5- cleaner it is not at all necessary to remove the same before painting, and in many instances there is a decided advantage to be gained by leaving the film formed by the cleaning spray upon the metal and to apply the paint, lacquer, or other coating directly upon the said-film. As a matter -of fact, the cleaning'solution formed with the organic sulphonic acid and combination of so]- vents -forms a desirable base for paints and i lacquers, and in some classes'of work, the pres- 40 ence of the film formed from the application of the cleaning fluid may take the .place of the customary primer coat.

It will, ofacourse, be appreciated that to enable the satisfactory deposition of the paint directly to the film of cleaning fluid, there be no excessive mechanical dirt or 83113986 upon the surface of said cleaning film. In the event that foreign matter should become deposited upon the cleaning film and that this cannot be removed by blasts of air, the coated metal can be washed, preferably with a solvent that will not entirely remove the cleaning film. Alcohol or benzene, either alone or mixed, can be used for this purpose, and while water might be used, it is preferred that no water he applied to the metal after the cleaning solution has been applied. Such solvents as those mentioned will not entirely remove,- insofar as I have been able to ascertain, the film of cleaning material on the metal.

It is believed that the many advantages of my improved cleaning process over the prior art are apparent.

I claim:

1. A cleaning compound for metal surfaces such as iron or steel, comprising an organic sulphonic acid, water, and a solvent for grease, said compound being substantially devoid of mineral acid and the salts thereof.

2. A cleaning compound for metal surfaces such as iron or steel, comprising an organic sulphonic acid, water, a solvent for grease, and carbon tetra-chloride said compound being substantially devoid of mineral acid and the salts thereof.

3. A cleaning compound for metal surfaces such as iron or steel, comprising an organic sulphonic acid. water, and alcohol said compound being substantially devoid of mineral acid and the compound being substantially devoid of mineralacid and the salts thereof.

5. A cleaning compound for metal surfaces such as iron or steel, comprising naphthalene,

sulphonic acid, water, and a solvent for grease said compound being substantially devoid of mineral acid and the salts thereof. 

